Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet #Preprint #PeerReviewMe: Warning: This is a unreviewed preprint. Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn. Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period. Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author). Background: Unhealthy alcohol use (UAU) is one of the major causes of preventable morbidity, mortality and associated behavioral risks worldwide. Although mobile health (mHealth) interventions can provide consumers with an effective means for self-control of UAU in a timely, ubiquitous, and cost-effective manner, to date, there is a lack of evidence about the health outcomes of these interventions. The components of these interventions are also unclear. Objective: To systematically review and synthesize the research evidence about the health outcomes of mHealth interventions for self-control of UAU and to explore the common components of these interventions. Methods: We systematically searched four electronic interdisciplinary databases: Scopus, PubMed (PMC), CINAHL Plus with full text and MEDLINE with full text. Search terms and MeSH headings, “mHealth”, “text message”, “self-control”, “self-regulation”, “alcohol*” were used individually or in combination to identify peer-reviewed publications in English from 2007 to 2017. We screened titles and abstracts, and assessed full-text articles as per inclusion and exclusion criteria. Data were extracted from the included articles according to CONSORT-EHEALTH checklist (V.1.6.1) by two authors independently. Data quality was assessed by the Mixed Methods Appraisal Tool. Data synthesis and analyses were conducted following the procedures for qualitative content analysis. Statistical testing was also conducted to test differences among groups of studies. Results: Twenty publications were included in the review. In fourteen studies (70%), mHealth interventions brought significant positive outcomes in improving participants’ health as measured by behavioral indicators (n=13), physiological indicators (n=1) and cognitive indicators (n=1). No significant health outcome was reported in the other five studies (25%). Surprisingly, a significant negative outcome was reported for the male participants in the intervention arm in one study (5%), but no change was found for the female participants. Five common components reported in mHealth interventions for consumer self-control of UAU were context, theoretical base, delivery mode, content and implementation procedure. The health outcomes were similar regardless of types of UAU, deployment setting, with or without non-mobile co-intervention and with or without theory. Conclusions: The major change brought by mHealth interventions for consumer self-control of UAU appeared to be improving behavior. There is still a lack of sound evidence on the effects of these interventions in improving the physiological and cognitive outcomes. More robust trials are needed to validate the short- and long-term health benefits and the contributing factors of mHealth interventions.